Rotating track cutting guide system

ABSTRACT

The present invention is a rotating track cutting guide system that maintains precise alignment of a bone saw with bone tissue. The rotating track cutting guide generally includes a track subassembly and cutting guide subassemblies attachable to the bone that is to be cut. The track subassembly supports an oscillating surgical saw driver. The track subassembly is removably securable to cutting guide subassemblies which are attachable to the desired bone to facilitate a series of controlled cuts. The design of the track subassembly stabilizes the oscillating saw driver and enables it to both rotate in the plane of the saw blade and move linearly along the track.

[0001] This application claims priority to U.S. Provisional ApplicationNo. 60/314,475 filed Aug. 23, 2001, the contents of which areincorporated herein in their entirety by this reference.

FIELD OF THE INVENTION

[0002] The present invention relates to instrumentation used forprecision bone cutting. More specifically, the invention relates to acutting guide apparatus for guiding a bone saw to allow for the surgicalpreparation of bone joint structures to facilitate the implantation ofartificial joint prostheses.

BACKGROUND OF THE INVENTION

[0003] In total knee arthroplasty, a damaged knee joint is replaced witha prosthesis to reproduce natural knee function. Multiple faceted cutsare made on the femur and at least one cut is made to the tibia toprepare the bone surface for application of the knee replacementprosthesis. These cut surfaces are preferably precisely angularlyaligned to each other and are planar to enable satisfactory mating withthe prosthesis.

[0004] In preparing the joint for a prosthesis, a series of cuts aremade to the inferior end of the femur and the superior end of the tibia.Exemplary femoral cuts are depicted in FIG. 1. Initially the femur iscut to create a flat surface (annotated “A” in the drawings) generallyperpendicular to the longitudinal mechanical axis of the bone. Next, twoflat cuts are made generally parallel to the longitudinal mechanicalaxis of the femur: one at the rear of the knee to remove the posteriorfemoral condyles B and another at the front of the knee C. Lastly, twochamfered cuts D, D′ are made at approximately a forty-five degree angleat the juncture of the perpendicular and the anterior and posteriorplanes (or “planed femoral surfaces”). The superior end of the tibia iscut off perpendicular to the longitudinal mechanical axis of the tibiain a fashion similar to femoral cut A.

[0005] Skeletal joints are subject to high degrees of mechanical stress.The secure attachment of joint replacement structures to the bone is,therefore, critical in determining the long-term success of the surgicalprocedure. The accuracy with which the bone ends are shaped is essentialto achieving a secure connection between the existing bone and animplanted prosthesis.

[0006] A number of studies have documented the correlation betweenimprecise bonding surface preparation and later complications for jointreplacement patients. Knee implant malpositioning due to deficient boneresecting technique contributes to poor long-term results by influencinga prosthesis' function, load distribution, wear and fixation.

[0007] These discoveries have led researchers to propose standards thatimprove the likelihood of post-surgical success. Sandborn et al.recommended that the gap between the bone and a porous-coated kneeimplant not exceed 0.5 mm for optimal bone ingrowth. P. M. Sandborn etal., The Effect Of Surgical Fit On Bone Growth Into Porous CoatedImplants, 12 Trans. Orthop. Res. Soc., 217 (1987). Cooke et al proposeda maximum cutting error of ±1 mm for proper bone fixation into aporous-coated prosthesis. T. D. Cooke et al., Universal Bone CuttingDevice For Precision Knee Replacement Arthroplasty And Osteotomy, 7 J.Biomed. Eng. 45, 50 (1985). These levels of accuracy are currentlydifficult to achieve.

[0008] Unfortunately, these currently exists as much as a ten-folddiscrepancy between the precision of the implant manufacturingtolerances (±0.2 mm) and the bone cutting process. Bone cements areoften used to fill the gap between resected bone tissue and theprosthesis. Even with the use of bone cement, however, an uneven cementmantle due to poor bone cutting can result in early prosthesisloosening.

[0009] To aid the surgeon in making the precise multiple bone cutsrequired for this type of surgery, various guides and devices have beenproposed. An initial group of devices are secured to the saw driver andto the patient and/or the surgical table. A second group includescutting guides that guide the saw blade, typically within a closefitting slot.

[0010] The first group includes, for example, U.S. Pat. No. 4,457,307,issued to Stillwell, which discloses a bone cutting device for totalknee replacements that is secured to the femur throughout its use. Withthis device, cuts are made both to the femur and the tibia. TheStillwell design requires removal of a large amount of soft tissue and asubstantial number of calculations and adjustments in order to make thecuts required for total knee replacement surgery.

[0011] U.S. Pat. No. 4,574,794, issued to Cooke et al., discloses aguide for supporting a bone saw driver. The Cooke guide includes acomplex system of parallel guide rods secured to the operating table aswell as to the long bones of the leg and the bones of the foot. Thedevice requires extensive fixation to the bone and numerous calculationsto generate the desired cuts on the knee joint. U.S. Pat. No. 5,007,912,issued to Albrektsson et al., discloses a cutting device mounted to aframe. The frame is connected to the patient's femur and to theoperating table. Similar to the Cooke device, this system requiresextensive manipulation of the saw driver and the patient to create therequired cuts.

[0012] U.S. Pat. No. 5,092,869, issued to Waldron, discloses a surgicalsaw guide, including retractable guide pins mounted in guide pin holderswhich stabilize the saw for translational movement along a linear axis.

[0013] U.S. Pat. Nos. 5,228,459 and 5,304,181, issued to Caspari et al.,disclose an apparatus that is affixed to the tibia and the ankle thatincludes a rack and pinion mechanism to linearly advance a surgicalmilling device to make the appropriate surface cuts for total kneereplacement surgery. The '181 patent discloses refinements to the deviceof the '459 patent.

[0014] U.S. Pat. No. 5,653,714, issued to Dietz et al., discloses amulti-component assembly that slides and pivots a milling head in orderto make the cuts required for knee replacement surgery.

[0015] The second group of cutting guide systems includes devices suchas that disclosed in U.S. Pat. No. 5,925,049, issued to Gustilo et al.The Gustilo patent discloses slotted cutting guides which are secured tothe bone end by screws or other fixtures. Slotted cutting guides assistin orienting the blade of a surgical bone saw during the cuttingprocess.

[0016] Despite these efforts, there remains room for improvement in thecreation of precise and accurate bone cuts with current cuttingtechnologies.

[0017] Devices that guide the saw body tend to be complex and cumbersometo set up, adjust and use. Orthopedic surgery is a physically demanding,labor intensive and time-consuming endeavor. Added instrument complexitytends to lead to longer procedures, which results in surgeon fatigue anda greater chance of surgical error.

[0018] Surgical cutting guides tend to obstruct the surgeon's view ofthe cutting site. This increases the risk of inadvertent damage tosurrounding tissue, and can reduce the accuracy of a cut.

[0019] The oscillating saw used by orthopedic surgeons can be guidedalong a surgical cutting guide by hand. Some cutting guides utilizeslots to provide a measure of blade control during surgery. There arenumerous limitations with this cutting methodology. The very nature ofresting an oscillating saw blade against another surface while the sawblade is in motion creates a certain degree of imprecision.

[0020] Also, to allow clearance for the saw in the kerf, surgical bonesaw teeth are set. That is, alternate teeth are offset from the centerof the blade so that the resulting cut is slightly wider than the blade,to prevent the blade binding in the kerf. Consequently, the guide slotmust be wide enough to receive the set of the teeth. This creates enoughclearance for the blade to toggle within the slot and substantiallyreduce the precision of the cut.

[0021] The surgeon's hand motions can cause the blade to toggle duringthe procedure and generate a non-planar bone surface. Vibrationsgenerated by the oscillating saw driver are transmitted to the hands ofthe surgeon and to the cutting guide, affecting the quality of theresected bone surface.

[0022] In addition, inadvertent blade contact with the inner slotsurface of a cutting guide dulls the blade teeth and damages the guideslot. Contact between the blade and guide can also result in a temporaryloss of blade control. Consequently, it is difficult to maintain the saworiented in the desired plane and angle.

[0023] Additionally, current cutting guide sets contain a large numberof precision machined parts. These parts are expensive and theirmultiplicity creates both added expense and complexity. It would bepreferable if the orthopedic surgeon had available a simpler cuttingguide system with relatively few parts.

[0024] Thus, there is a need for a surgical saw guide that allows forthe precise faceting of bone ends to facilitate the implantation oforthopedic prostheses. The guide should be simple to set up and usewhile creating precision planar cuts in bone tissue. It is preferredthat the guide minimize saw blade damage and wear and that the guideminimize vibrational energy transfer to the surgeon's hands and thepatient's bone. It would be preferable to minimize the amount of visualobstruction presented by the cutting guide.

SUMMARY OF THE INVENTION

[0025] The present invention fulfills the above needs by providing arotating track cutting guide system that maintains precise alignment ofa bone saw with bone tissue. The rotating track cutting guide systemgenerally includes a track subassembly and cutting guide subassembliesattachable to the bone that is to be cut. The track subassembly supportsan oscillating surgical saw driver. The track subassembly is removablysecurable to cutting guide subassemblies which are attachable to thedesired bone to facilitate a series of controlled cuts. The design ofthe track subassembly stabilizes the oscillating saw driver and enablesit to both rotate in the plane of the saw blade and move linearly alongthe track. In conjunction with specially designed cutting guidesubassemblies, use of the track subassembly enables a surgeon using therotating track cutting guide system to perform all the necessarysurgical cuts required for a knee replacement with great accuracy andprecision. The rotating track cutting guide system is adaptable to anopen frame design to improve visibility of the surgical site duringresection. Although the rotating track cutting guide system will bedescribed in the context of total knee arthroplasties, it should beunderstood that the invention may be applied to various other surgicalprocedures.

[0026] The track subassembly includes a rotating driver carriage thatsupports an oscillating saw driver. The driver carriage rests upon atrack that has an alignment member that enables the track to removablyattach to various positioning and cutting guides. The alignment memberallows immediate fixation of the track onto the cutting guidesubassembly, while fastening members provide for ready attachment andremoval. The use of a stabilizing track in conjunction with cutting andpositioning guides results in a synergistic effect that enables the userto resect bone to great accuracy and precision along a plane.

[0027] The present invention provides a cutting platform whereby theoscillating saw driver, the cutting guide and the bone to be cut arefixed relative to one another except in the plane in which the cut isbeing made. The stabilization of movement affords the surgeon excellentcontrol and enables the physician to perform precise and accurate cuts.

[0028] Further, the rotating track cutting guide system minimizes bladedamage and wear caused by inadvertent contact between the blade and thecutting guide. The resulting retention of blade sharpness throughout theprocedure produces a smoother, flatter, more precisely cut bone surfacethan is otherwise achievable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1a is a perspective view of a resected distal femur showingfacets created in preparation for placement of a knee prosthesis;

[0030]FIG. 1b is a profile view of a distal femur and a proximal tibiauncut;

[0031]FIG. 1c is a profile view of a resected distal femur and aproximal tibia as faceted for total knee arthroplasty;

[0032]FIG. 2 is a side perspective view of a rotating track cuttingguide system of the present invention positioned as attached to a femur,with phantom lines depicting a femur and a saw apparatus;

[0033]FIG. 3 is a top perspective view of a track subassembly inaccordance with the present invention;

[0034]FIG. 3a is a detail view of a second embodiment of the end of thetrack subassembly (taken at the position of 3 a of FIG. 3);

[0035]FIG. 4 is a perspective view of the track subassembly as depictedin FIG. 2, but with the subassembly inverted, phantom lines depicting asaw apparatus;

[0036]FIG. 5 is an exploded top perspective view of a driver carriageused in accordance with the present invention;

[0037]FIG. 6 is an exploded front perspective view of the distal femurand proximal tibia cutting guide subassembly and track in accordancewith the present invention;

[0038]FIG. 6a is a perspective view of an alternative embodiment of adistal femur and proximal tibia cutting guide, attached to anintramedullary alignment system (depicted in phantom);

[0039]FIG. 7 is rear perspective view of an anterior and posteriorfemoral cutting guide subassembly in accordance with the presentinvention;

[0040]FIG. 8 is top perspective view of a posterior cutting guide inaccordance with the present invention;

[0041]FIG. 9 is a bottom perspective view of the posterior cutting guidein accordance with the present invention;

[0042]FIG. 10 is a front perspective view of an anterior cutting guidein accordance with the present invention;

[0043]FIG. 11 is rear perspective view of the anterior cutting guide inaccordance with the present invention;

[0044]FIG. 12 is an exploded, top perspective view of the anteriorcutting guide with the detachable femoral anterior reference inaccordance with the present invention;

[0045]FIG. 13 is a bottom perspective view of the detachable anteriorreference in accordance with the present invention;

[0046]FIG. 14 is a top perspective view of a chamfer cutting guidesubassembly in accordance with the present invention;

[0047]FIG. 15 is a cross-sectional view of the chamfer cutting guidesubassembly of the present invention taken along line 15-15 of FIG. 14;

[0048]FIG. 16 is a perspective view of an alternative embodiment of adistal femur and proximal tibia cutting guide and track in accordancewith the present invention;

[0049]FIG. 17 is a perspective view of a first alternative embodiment ofthe rotating track cutting guide system including a multipurpose cuttingguide and multipurpose track, with phantom lines depicting a bone sawand a femur;

[0050]FIG. 18 is a perspective view of the multipurpose cutting guideand multipurpose track of FIG. 17 assembled, with phantom linesdepicting a bone saw and a femur;

[0051]FIG. 19 is a perspective view of a second alternative embodimentof the multipurpose track subassembly in accordance with the presentinvention, with phantom lines depicting a bone saw and a femur;

[0052]FIG. 20 is a graph summarizing experimental results for aprecision comparison between the rotating track cutting guide and aprior art cutting system, each system cutting plastic-coated knees;

[0053]FIG. 21 is a graph summarizing experimental results for aprecision comparison between the rotating track cutting guide and aprior art system, each system cutting cadaver knees;

[0054]FIG. 22 is a profile view of a third alternative embodiment of therotating track cutting guide system engaged to a femur; and

[0055]FIG. 23 is a perspective view of the embodiment of FIG. 22 with abone saw and a femur depicted in phantom.

DETAILED DESCRIPTION OF THE INVENTION

[0056] The rotating track cutting guide system 30 of the presentinvention, as depicted in the drawings, generally includes a tracksubassembly 32 and a variety of bone cutting guides. Bone cutting guidesinclude an anterior and posterior femoral (APF) cutting guide 36, adistal femur and proximal tibia (DFPT) cutting guide 38 and a chamfercutting guide 40. Track subassembly 32 is adapted to be removablyaffixed to any of the bone cutting guides. Bone cutting guides areadapted to be removably affixed to bone structures via clamps (notshown), screws (not shown), pins (not shown), drill bits 33 or any othermeans known to those skilled in the orthopedic arts. Bone cutting guidesmay be adapted to receive handlebars 35.

[0057] Referring to FIGS. 2, 3 and 4, track subassembly 32 supports anoscillating saw driver 42 and is depicted attached to distal femur andproximal tibia cutting guide 38 which is, in turn, attached to femur 44.Oscillating saw driver 42 drives saw blade 46.

[0058] Track subassembly 32 generally includes track 48 and drivercarriage 50. Driver carriage 50 is slidably carried on track 48 and isadapted to support oscillating saw driver 42. Oscillating saw driver 42may be, for example, a 3M oscillating head L120B in combination with a3M Maxi Driver II L100. Track 48 is adapted to be removably attachableto any of cutting guides 36, 38, 40.

[0059] Referring to FIG. 5, driver carriage 50, includes superior driverbrace 52, inferior driver brace 54 and endcap 56. Superior driver brace52 presents counterbored holes 58, 60, 62, 64 adapted to receivethreaded fasteners 66, 68, 70, 72 through top brace face 73. Threadedfasteners 66, 68, 70, 72 thread into fastening holes 74, 76, 78, 80 ininferior driver brace 54, to secure superior driver brace 52 to inferiordriver brace 54. Inner brace contact surfaces 77, 79 of superior driverbrace 52 and inferior driver brace 54 conform to oscillating saw driver42.

[0060] Endcap 56 includes superior circular plate 81, inferior circularplate 82 and cylindrical spacer 84. Inferior circular plate 82 presentscounterbored hole 86 adapted to receive threaded fastener 88.Counterbored hole 86 is located proximate the center of inferiorcircular plate 82. Threaded fastener 88 is receivable into threaded bore90 located in inferior driver brace 54.

[0061] Referring particularly to FIG. 3, track 48 presents track slot92, alignment peg 94, and counterbored alignment hole 96 adapted toreceive fastener 97. Track 48 further presents superior track face 98,inferior track face 100, front track face 102, back track face 104,inner track face 106 and side track faces 108. Track slot 92, as definedby inner track faces 106, is of appropriate width to slidably receivecylindrical spacer 84. The thickness of track 48, as defined as thedistance between superior track face 98 and inferior track face 100, isadapted to be received between superior circular plate 80 and inferiorcircular plate 82.

[0062] Front end 110 of track 48 is adapted to be secured to bonecutting guides 36, 38, 40. Front end 110 includes alignment peg 94 andcounterbored alignment hole 96. Counterbored alignment hole 96 receivesthreaded fastener 97. In another embodiment, depicted in FIG. 3a, frontend 110′ includes alignment pins 114, recesses 116 and alignment clips118.

[0063] Referring to FIG. 6, distal femur and proximal tibia cuttingguide 38 generally includes positioning guide 120 and cutting guide 122.DFPT cutting guide 38 is adapted to receive track 48.

[0064] Positioning guide 120 presents attachment shelves 124, 126, pegholes 128, 130, track fastening holes 132, 134, pin holes 136, 138,diagonal pin holes 144, 146, handlebar holes 148, 150, and guidefastening holes 152, 154. Guide fastening holes 152, 154 are adapted toreceive guide fasteners 156, 158.

[0065] Cutting guide 122 presents cutting slot 160, intramedullaryattachment holes 162, 164 and counterbore guide holes 166, 168. Alsoshown in phantom in FIG. 6a is intramedullary alignment system 170.Intramedullary alignment system 170 includes intramedullary alignmentrod 172, bracket 174 and angle positioner 175.

[0066] Referring to FIG. 16, another embodiment of DFPT cutting guide38″ is shown. This embodiment of DFPT cutting guide 38″ presentsattachment slots 176, 178, attachment bosses 180, 182, and attachmentclip receivers 184, 186. This embodiment further presents diagonal pinholes 144 and handlebar holes 148 and slot 160 similar to the initialembodiment.

[0067] Referring to FIG. 7, APF cutting guide 36 generally includesposterior cutting guide 188 and anterior cutting guide 190. Posteriorcutting guide 188 generally includes body 192 and posterior condylereferencing paddles 194, 196.

[0068] Referring particularly to FIGS. 8 and 9, body 192 presentscondyle cutting slots 198, 200, sizing slot 202 and notch 204. Notch 204is located between posterior condyle referencing paddles 194, 196.Attachment shelves 206, 208 are located at the juncture betweenposterior condyle referencing paddles 194, 196 and body 192. Eachattachment shelf 206, 208 further includes fastening holes 210 and pegholes 212. Attachment shelves 206, 208 are adapted to receive track 48.

[0069] Sizing slot 202 includes inner sizing slot grooves 214, 216 andinner sizing slot top face 218. Inner sizing slot top face 218 presentsa plurality of sizing holes 220. Body 192 further presents handlebarattachments 222, 224 and diagonal fixation pinholes 226, 228 orienteddiagonally inward therethrough.

[0070] Referring to FIGS. 10, 11 and 12, anterior cutting guide 190generally includes sizing ledge 230 and guide body 232. Sizing ledge 230generally includes sizing side ridges 234, 236, sizing ledge top face238 and sizing ledge bottom face 240. Sizing ledge top face 238 presentssizing holes 242 therethrough. Sizing ledge 230 is dimensioned so as tobe slidably received into sizing slot 202 as depicted in FIGS. 8 and 9.

[0071] Guide body 232 includes inner ring 244 and attachment ledge 246.In a first embodiment of anterior cutting guide 190, inner ring 244 iscut entirely through the thickness of guide body 232. In a secondembodiment inner ring 244 is cut partially through the thickness ofguide body 232, and a cutting slot 248 is cut through the remainingthickness. In the second embodiment attachment buttress 250 is present.

[0072] Attachment ledge 246 includes fastening hole 252 and peg hole254. Attachment ledge 246 is adapted to receive track 48.

[0073] Attachment ledge 246 is also adapted to receive detachablefemoral reference 256. Referring to FIG. 13, detachable femoralreference 256 generally includes body 258, L-bracket 260 and attachmentslot 262.

[0074] Referring to FIGS. 14 and 15, chamfer cutting guide 40 generallyincludes side plates 264, 266, attachment guide plates 268, 270 andcentral guide plate 272. Side plates 264, 266 each present handlebarhole 274 and diagonal fixation hole 276. Attachment guide plate 268presents anterior fastening hole 278 and anterior peg hole 280.Attachment guide plate 270 presents posterior fastening hole 282 andposterior peg hole 284. Central guide plate 272 presents a plurality ofguide positioning holes 286. Attachment guide plate 268 and centralguide plate 272 define anterior cutting slot 288. Attachment guide plate270 and central guide plate 272 define posterior cutting slot 290.Bottom side attachment guide plates 268, 270 and central guide plate 272define bone contacting face 292.

[0075] Referring to FIGS. 17 and 18, another embodiment of rotatingtrack cutting guide system 30 is depicted. This embodiment generallyincludes multipurpose cutting guide 294 and multipurpose track 296.

[0076] Multipurpose cutting guide 294 is generally an open frame guide.Multipurpose cutting guide 294 includes perpendicular cut adaptor 300and chamfer cut adaptors 302. Multipurpose cutting guide 294 defines aplurality of alignment rod receivers 304. Perpendicular cut adaptor 300includes perpendicular rod receivers 306. Chamfer cut adaptors 302include chamfer rod receivers 308. Multipurpose cutting guide 294defines a window 310. Window 310 has a superior edge 312 and an inferioredge 314.

[0077] Multipurpose track 296 is generally similar to track 48 exceptfor the addition of a terminal block 316 secured at the end thereof.Terminal block 316 supports alignment rods 318 and presents upper edge320. In one embodiment, depicted in FIG. 19 terminal block 316 also isperforated by guide slot 322. Guide slot 322 is sized to receive sawblade 46.

[0078] Referring to FIGS. 22 and 23, an additional embodiment of thepresent invention includes curved track 324. Driver carriage 50 isslidably and rotatably retained on curved track 324. Otherwise thisembodiment is similar in structure to the foregoing embodiments.

[0079] In operation, rotating track cutting guide system 30 is assembledin concert with oscillating saw driver 42. Referring to FIG. 5, superiordriving brace 52 and inferior driving brace 54 are separated andassembled to grip oscillating saw driver 42 as depicted in FIG. 4. Sawblade 46 is attached to oscillating saw driver 42. Track 48 may then beconnected to any of bone cutting guides 36, 38, 40.

[0080] Referring particularly to FIGS. 2 and 6, in preparing to make aninitial cut on femur 44, distal femur and proximal tibia cutting guide38 is secured to femur 44 via clamps, screws, pins or drill bits or anyother means known in the orthopedic arts. If desired, handle bars 35 maybe secured to DFPT cutting guide 38 to allow an assistant to the surgeonto help support DFPT cutting guide 38 during the cutting process. Track48 is secured to DFPT cutting guide 38 prior to cutting.

[0081] Referring particularly to FIG. 6, DFPT cutting guide 38 may bedisassembled into positioning guide 120 and cutting guide 122. Forattachment, front end 110 of track 48 is inserted so that it rests onone of attachment shelves 124, 126 and so that alignment peg 94 engagesinto peg hole 128, 130. Thereupon, a fastener 131 may be insertedthrough counterbored alignment hole 96 and threaded into track fasteninghole 132, 134. Once fastener 131 is tightened in place, cutting guide122 is assembled to positioning guide 120. This is achieved by insertingfasteners 156, 158 through cutting guide counterbored holes 166, 168 oncutting guide 122 and tightening fasteners 156, 158 against fasteningholes 152, 154.

[0082] Referring again to FIGS. 2, 3 and 4, oscillating saw driver 42may then be moved linearly and rotationally in a fixed plane because ofthe interaction between driver carriage 50 and track 48. End cap 56 issecurely and slidably engaged to track slot 92, thereby allowing drivercarriage 50, along with oscillating saw blade 46, to move within a fixedplane aligned with cutting slot 160 if present.

[0083] Oscillating saw driver 42 may then be advanced through cuttingslot 160 in order to make an initial planar cut across the inferior endof femur 44. Because of the interconnection of rotating track cuttingguide system 30 to femur 44, this cut will be planar and smooth.

[0084] After this initial cut is made, distal femur and proximal tibiacutting guide 38 may be unfastened from femur 44 and removed.

[0085] Making the initial femoral cut with the alternate embodiment ofDFPT cutting guide 38 depicted in inset 3 a and FIG. 16 requires aslightly different procedure. In this embodiment, positioning guide 120and cutting guide 122 are combined into a single unit. DFPT cuttingguide 38 is secured to femur 44 by the insertion of drill bits 33 intofastening holes 136, 138. Track 48 is then inserted into attachment slot176, 178, and alignment of track 48 is achieved through the interactionof attachment bosses 180, 182 with recesses 116. Upon insertion,alignment clips 118 engage attachment clip receivers 184, 186 to securetrack 48 to DFPT cutting guide 38. Thereafter, the initial femoral cutis made as described above.

[0086] Referring to FIGS. 7-12, anterior and posterior femoral cuttingguide 36 is adapted to be placed against the planar resected bonesurface previously produced by the use of DFPT cutting guide 38. Toproperly orient APF cutting guide 36, body 192 is placed on the resectedbone surface so that posterior condyle referencing paddles 194, 196 arein contact with the condyles on femur 44 and notch 204 is aligned withthe intercondylar notch on femur 44.

[0087] After properly orienting anterior and posterior femoral cuttingguide 36, the size of femur 44 may be measured using detachable femoralreference 256. Detachable femoral reference 256 is placed so thatattachment slot 262 engages attachment ledge 246. The femur 44 may thenbe sized by pressing posterior condyle referencing paddles 194, 196against the femoral condyles and pressing L-bracket 260 of detachablefemoral reference 256 against the anterior femoral surface.

[0088] Thereafter, APF cutting guide 36 is secured to femur 44 by anymeans known to the orthopedic arts. If necessary, handlebars 35 may besecured to handlebar attachments 222, 224 to enable an assistant to holdand restrain the motion of APF cutting guide 36 to provide additionalstability during the cutting process.

[0089] Resection of the anterior portion of femur 44 may then beaccomplished. Track subassembly 32 is secured to attachment ledge 246.Oscillating saw driver 42 may then be advanced along track 48 to makethe appropriate cut to the anterior region of femur 44.

[0090] Resection of the posterior portion of the femoral condyles isaccomplished by sequentially securing track subassembly 32 to attachmentshelves 206, 208. Oscillating saw driver 42 may then be advanced androtated along track 48 as needed to accomplish the required posteriorfemoral condyle cuts. Once the required resections are made, APF cuttingguide 36 is removed from femur 44.

[0091] Next, referring to FIGS. 14 and 15, anterior and posteriorchamfer cuts may be made to femur 44. Chamfer cutting guide 40 issecured to the resected surface of femur 44 by use of any means known tothe orthopedic art such that bone contacting face 292 is flush with theresected femur surface A. Track subassembly 32 is then secured to one ofattachment guide plates 268, 270. To make the posterior chamfer cut,track subassembly 32 is secured at anterior peg hole 280 and anteriorfastening hole 278. Oscillating saw driver 42 may then be advanced alongtrack 48 and rotated as need be to make the required resection. Theanterior chamfer cut is made in a similar fashion, attaching tracksubassembly 32 at posterior peg hole 284 and posterior fastening hole282. If desired, handlebars 35 may be secured at handlebar holes 274 inorder to provide additional stabilization of chamfer cutting guide 40.

[0092] To effect resection of the proximal portion of the tibia, aprocedure similar to that used for resecting the distal portion of femur44 is followed.

[0093] Referring to FIGS. 17 and 19, to utilize multipurpose cuttingguide 294 for the initial femoral cut, multipurpose cutting guide 294 issecured to the anterior surface of femur 44 by any means known to theorthopedic arts. Note that the presence of window 310 providesconvenient visibility of the bone structure for the surgeon.

[0094] Once multipurpose cutting guide 294 is in position, multipurposetrack 296 may be engaged to multipurpose cutting guide 294 as depictedin FIG. 18. Thereupon, oscillating saw driver 42 and saw blade 46 may beadvanced along multipurpose track 296 in order to make the appropriatecuts.

[0095] Note, referring to FIG. 18, that when engaged, terminal block 316and superior edge 312 combine to form an effective guide slot for sawblade 46. In another alternate embodiment, depicted in FIG. 19, terminalblock 316 includes guide slot 322 to provide additional stabilization ofsaw blade 46.

[0096] After making the initial femoral cut, as depicted in FIG. 17,multipurpose cutting guide 294 may be relocated to make anterior andposterior femoral cuts. This orientation is depicted in FIG. 18. Aftermultipurpose cutting guide 294 is secured to femur 44 at the location ofthe initial femoral cut, multipurpose track 296 may be engaged to makethe anterior femoral cut. Once the anterior femoral cut is completed,multipurpose track 296 may be removed, rotated 180°, around thelongitudinal axis of multipurpose track 296 and replaced on multipurposecutting guide 294 in order to make the posterior femoral cut.

[0097] After the posterior femoral cut is made, multipurpose track 296may be removed and relocated so as to engage chamfer cut adaptor 302 inorder to make a first chamfer cut. Thereafter, multipurpose track 296may be located to the other chamfer cut adaptor 302 in order to make thesecond chamfer cut to this resected femur 44.

[0098] Note that when placed on chamfer cut adaptors 302, upper edge 320of terminal block 316 provides support for saw blade 46 and superioredge 312 or inferior edge 314 also provide support for saw blade 46.This additional support serves to improve the planar quality of the cutsmade.

[0099] Multipurpose cutting guide 294 both reduces the number of partsnecessary for the rotating track cutting guide system 30 and allows theanterior and posterior femoral cuts as well as the chamfer cuts to bemade without the necessity of repositioning or replacing the cuttingguide.

EXAMPLES

[0100] A quantitative assessment of the final design of the rotatingtrack cutting guide system was performed to judge its effectiveness. Itscapabilities were compared to cutting guides from a typical kneereplacement system, the Exodus® System (Orthopaedic Innovations,Minneapolis, Minn.). Three experiments were performed to appraise theefficacy of the rotating track cutting guide system. The followingexperiments were performed:

[0101] A. Precision Analysis: Evaluated the each system's capacity toreproducibly cut in the same plane.

[0102] B. Blade Wear Analysis: Examined the cutting guides' success atreducing blade wear.

[0103] C. Femoral Component Fit Analysis: Provided information on theamount of contact between prosthesis and the resected bone surface todetermine the accuracy with which the cut bone fit the prosthesis.

[0104] A. Precision Analysis

[0105] The precision analysis evaluated a cutting guide's ability to cutconsistently in the same plane. After distal femoral condyle resectionin a simulated total knee arthroplasty, the angle between the lateraland medial femoral condylar planes was measured. The precision of thecut was defined as the absolute value of the angular difference betweenthe two condylar planes.

[0106] Methods for Experiment A1

[0107] Twelve 1145 urethane foam knees (Pacific Research Laboratories,Inc., Vashon, Wash.) were used. The rotating track cutting guide systemand the Exodus® System were each tested with six knees and six newK-2000-25 3M Maxi-driver® blades (Komet Medical, Savannah, Ga.). Aftersecuring each cutting guide to a femur, the distal femoral condyles wereresected. A Craftsman® Magnetic Universal Protractor (Sears, HoffmanEstates, Ill.) measured the angle of the lateral and medial condylarplanes with respect to the ground. The protractor had an accuracy of±0.5° and was maintained in a consistent orientation when placed on eachcondyle.

[0108] When measuring the condylar plane orientation, the angleindicated by the protractor was read by two individuals to account foruser error. Both individuals separately measured the angles associatedwith the resected medial and lateral condylar planes. Each individualthen calculated the angular difference between the two condylar planesand these values from the two individuals were compared. If the angulardifference values differed, then the angles associated with the resectedmedial and lateral condylar planes were re-measured by each individual.

[0109] Methods for Experiment A2

[0110] The same procedure in Experiment A1 was performed, except thatfemora from twelve 1107-2 plastic-coated urethane foam knees were used.The 1107-2 urethane foam knees had a hard urethane elastomer cortex andwere intended to model real bones more closely than the urethane foambones.

[0111] Methods for Experiment A3

[0112] The same procedure in Experiment A1 was performed, except thatthe femora from fresh-frozen cadaver knees were used.

[0113] Analysis for the Precision Experiments

[0114] For the precision analysis, the absolute value of the angulardifference between the two condylar planes was computed. For all theknees, a Fisher's Exact Test of Independence was used. This analysis istwo-tailed test using a 2×2 table and compared the rate of existence ofa zero difference between the Exodus® System and the rotating trackcutting guide system. The experimental hypothesis was that the rotatingtrack cutting guide system would have a higher rate of zero angulardifference than the Exodus® System. TABLE 1 Angular Difference (Degrees)Between the Condyles When Using the Exodus ® System and the RotatingTrack Cutting Guide to Resect Foam Femora Exodus ® System Rotating TrackCutting Guide System Bone 1 0 0 Bone 2 0 0.5 Bone 3 0 0 Bone 4 0.5 0Bone 5 0 0 Bone 6 0 —

[0115] TABLE 2 Angular Difference (Degrees) Between the Condyles WhenUsing the Exodus ® System and Rotating Track Cuffing Guide to ResectPlastic-coated Femora Exodus ® System Rotating Track Cutting GuideSystem Bone 1 0 0 Bone 2 0.5 0 Bone 3 0.5 0 Bone 4 1 0 Bone 5 0.5 0 Bone6 0.5 0

[0116] TABLE 3 Angular Difference (Degrees) Between the Condyles WhenUsing the Exodus ® System and Rotating Track Cutting Guide to ResectCadaver Femora Exodus System Rotating Track Cutting Guide Bone 1 2.5 0Bone 2 1.5 0 Bone 3 0 0.5 Bone 4 0 0 Bone 5 0.5 0 Bone 6 0 0

[0117] Discussion

[0118] For the Precision Analysis using the foam femora and cadaverfemora, no significant differences could be found between theperformances of the two cutting systems. When the cadaver femora wereresected, the largest indicator of the different levels of performancebetween the two cutting systems stemmed from the 2.5 degree angulardifference between the resected medial condylar plane and the lateralcondylar plane when using the Exodus® System. In our study, however, thesample size of six did not allow the results to be statisticallysignificant. These results suggested that a larger sample size would beappropriate for a definitive statistical comparison.

[0119] The Fisher's Exact Test of Independence for plastic-coated bonesindicated that the rotating track cutting guide system had asignificantly higher rate of zero angular difference than the Exodus®System (P=0.015). The better performance of the rotating track cuttingguide system in our study suggested that the rotating track cuttingguide system cuts more precisely than the Exodus® System.

[0120] B. Blade Wear Analysis

[0121] The investigators made an examination of the blade wearassociated with total knee arthroplasty. Reduced blade wear reflects thecutting guides' effectiveness for minimizing blade damage. Retainedblade sharpness results in the more precise cutting of bone and asmoother bone surface.

[0122] Methods for Experiment B1

[0123] Two new K-2000-25 3M Maxi-driver® blades and 12 new 1145 urethanefoam knees were obtained. One blade and six knees were randomly assignedto the cutting guides of the Exodus® System. The rotating track cuttingguide system's cutting guides used the remaining blade and knees. Theblades for the Exodus® and the rotating track cutting guide system'sguides were weighed before their use. After performing all the femoraland tibial cuts in a simulated total knee arthroplasty, each blade wassoaked overnight in acetone, dried and weighed. Repeated weighing of theblade ensured that a consistent blade weight value was obtained. A totalof six simulated knee arthroplasties were performed using each blade andsystem, and the blade was weighed after each of the six procedures. Thechange in blade weight provided an indication of the average amount ofblade wear associated with the use of each instrumentation system afterone total knee arthroplasty.

[0124] Methods for Experiment B2

[0125] This experiment was similar to Experiment B1, but required theuse of 12 new 1107-2 plastic-coated urethane foam knees. For additionalqualitative information on blade damage, scanning electron microscopyprovided 20×images of the blade teeth. SEM images of each blade weretaken before the first arthroplasty and after the sixth procedure.Providing descriptive rather than quantitative information on bladedamage, the images depicted the cumulated blade wear associated witheach instrumentation system.

[0126] Analysis for the Blade Wear Experiments

[0127] The mean blade wear loss for each cutting system was calculatedfrom six total knee arthroplasties. For the foam and plastic-coatedknees, a repeated measures ANOVA compared the performance between thetwo cutting systems. The hypothesis was that the rotating track cuttingguide system would result in less blade weight loss compared with theExodus® System.

[0128] Results TABLE 4 Blade Weight Loss Comparison Between the Exodus ®System and the Rotating Track Cutting Guide System After PerformingTotal Knee Arthroplasty on Six Foam Knees Exodus ® System Rotating TrackCutting Guide System Trial 1 1.65 mg 0.125 mg  Trial 2  1.2 mg 0.125 mg Trial 3 0.85 mg 0.07 mg Trial 4  2.5 mg 0.03 mg Trial 5  0.7 mg  0.2 mgTrial 6  1.6 mg  0.0 mg Total  8.5 mg 0.55 mg Mean 2.56 mg 0.16 mg

[0129] TABLE 5 Blade Weight Loss Comparison Between the Exodus ® Systemand the Rotating Track Cutting Guide System After Performing Total KneeArthroplasty on Six Plastic-coated Knees. Exodus System Rotating TrackCutting Guide System Trial 1 −2.7 mg    0.3 mg Trial 2 9.8 mg 1.55 mgTrial 3 1.5 mg   0 mg Trial 4 0.7 mg  0.2 mg Trial 5 0.4 mg   0 mg Trial6 1.25 mg   0.1 mg Total  11 mg 2.15 mg Mean 4.1 mg 0.67 mg

[0130] Blade damage was also qualitatively assessed by examining SEMimages. The images with the Rotating track cutting guide systemexhibited less cumulative blade damage than the Exodus® System.

[0131] Discussion

[0132] In the Blade Wear Analyses, a repeated measures ANOVA yielded astatistically significant difference in the blade wear between therotating track cutting guide system and the Exodus® System (P=0.03).When resecting foam knees, there was often an order of magnitudedifference in the blade weight loss between the rotating track cuttingguide system and the Exodus® System. Use of the rotating track cuttingguide system and the Exodus® System to resect plastic-coated kneesshowed a similar difference. There also existed a consistent wearpattern between each cutting system when resecting foam bones. The wearpattern, however, became less consistent when resecting plastic-coatedbones. Additionally, the negative difference after the first blade weartrial for the Exodus® System was most likely due to plastic residue thatremained on the blade after cleaning. Given the small sample size, moredefinitive conclusions can only be made after testing a larger number ofblades.

[0133] The SEM images provided visual information that the rotatingtrack cutting guide system was more effective in the retention of bladeteeth sharpness than the Exodus® System. For the blade used by therotating track cutting guide system, there was no deformation of theteeth closest to the sides of the saw blade, unlike with the blade usedby the Exodus® System. The blade used by the rotating track cuttingguide system, however, did have one row of blade teeth that wassignificantly worn. This wear pattern was probably due to theinterference of the saw blade with the posterior cutting guide slots onthe anterior and posterior femoral cutting guide subassembly. Theexperimental design of the rotating track cutting guide system did notinclude a method to attach and use the track subassembly to help guidethe saw blade to resect the posterior femoral condyles. Consequently,the row of damaged teeth probably occurred from the saw blade not beingoriented and stabilized with a track.

[0134] C. Femoral Component Fit Analysis

[0135] This experiment indicated the effectiveness of the cuttinginstrumentation through a fit assessment of the femoral component ontothe femur. Although the use of PMMA allows a surgeon a greater margin oferror when cutting bone, an uneven cement mantle can result in earlyprosthesis loosening. For this analysis, Ultra Low Pressurex® film(Sensor Products, Inc., East Hanover, N.J.) provided an image of thecontact between the underside of the femoral component and the resectedfemoral surface. Decreased cutting effectiveness during resection wouldresult in reduced contact area.

[0136] Methods for Experiment C1

[0137] In this experiment, 12 new plastic-coated femora and 12 newK-2000-25 3M blades were obtained. Six blades and femora were randomlyselected and used with the Exodus cutting guides. The rotating trackcutting guide system used the remaining blades and bones. Each systemwas used to perform the distal, anterior, posterior, anterior chamferand posterior chamfer femoral cuts. The two halves of the Ultra LowPressurex® film, the Transfer Sheet and the Developer Sheet, wereindividually cut into 3″×4.5″ rectangles and folded to conform to thedistal portion of the resected femur and to each other. After theTransfer Sheet and the Developer Sheet were gently placed upon oneanother to avoid inadvertent film activation, the femoral component wasplaced onto the distal femur. The high sensitivity Pressurex® film wasused so that film activation would not depend solely on the impact forceapplied by the surgeon when placing the femoral component onto the bone.Contact between the underside of the femoral component and the resectedfemoral surface broke the chemical-filled microcapsules on the TransferSheet. This chemical reacted with the color developing material on theDeveloper Sheet and generated a residual red stain at the regions wherethe prosthesis and bone contacted. Unstained Pressurex® film indicatedthe location of the gaps between the implant and the cut bone.

[0138] Methods for Experiment C2

[0139] The same procedure as in experiment C1 was performed, except thatfresh-frozen cadaver knees were used rather than plastic-coated knees.

[0140] Analysis

[0141] The contact area between the component and femur was calculatedusing SigmaScan® software. The data were normalized by dividing thecontact area by the total area of the underside of the femoralcomponent. After averaging the percent of contact data for the sixfemora with the two cutting systems, their means were compared.Plastic-coated knees required a two-sample t test for statisticalanalysis. The use of paired cadaver knees required a paired t-test foranalysis. The hypothesis was that the rotating track cutting guidesystem would result in a higher percent of contact area than the Exodus®System

[0142] Results

[0143] Results of the femoral fit component fit analysis utilizingplastic coated femora and cadaver are summarized in graphs depicted asFIGS. 20 and 21 respectively.

[0144] Discussion

[0145] For the Femoral Component Fit Analysis using plastic-coatedbones, use of the rotating track cutting guide system resulted instatistically significant increased contact between the underside of thefemoral component and the resected femur than the Exodus® System (mean42% vs. 28%, P=0.039). In the Femoral Component Fit Analysis withcadaver bones, use of the rotating track cutting guide system alsoresulted in statistically significant increased contact between theunderside of the femoral component and the resected femur than theExodus® System (mean 44% vs. 31%, P=0.021). Both results indicated thatproper use of the rotating track cutting guide system resulted ingreater contact between the resected bone surface and the prosthesis.

[0146] The distribution of contact percentages between each system maybe attributed to how the cutting systems were designed and manufactured.For the Exodus® System, the cutting guide must be manually adjusted tothe appropriate size before performing the chamfer cuts. A millimeter ofdifference can influence whether the femoral component will fit onto theresected bone surface. Consequently, half a millimeter of difference inthe sizing of the cutting guide may have caused the contact percentageto range from 20-40%.

[0147] For the rotating track cutting guide system, one of the diagonalfixation holes of the medium chamfer cutting guide subassembly broke.This occurred as cadaver femur 3 was being resected. Consequently, therotational motion of the medium chamfer cutting guide subassembly duringthe resecting process resulted in a low area contact percentage betweenthe resected femoral surface and the prosthesis. The remainingvariability in the performance of the rotating track cutting guidesystem was probably due to minor rotational motion of the large chamfercutting guide subassembly during surgery.

[0148] D. Experiment Summary

[0149] The various analyses provided insight into the capabilities ofthe rotating track cutting guide system. The results of the PrecisionAnalysis suggested that the rotating track cutting guide system resectedthe distal femur more precisely than a conventional cutting system. TheBlade Wear Analysis proved a clearer suggestion that the rotating trackcutting guide system produced statistically significant less blade wearon a saw blade than the Exodus® System. Use of the rotating trackcutting guide system also resulted in statistical significant increasedcontact between the underside of the femoral component and the resectedfemur surface.

[0150] The present invention may be embodied in other specific formswithout departing from the spirit of any of the essential attributesthereof; therefore, the illustrated embodiments should be considered inall respects as illustrative and not restrictive, reference being madeto the appended claims rather than to the foregoing description toindicate the scope of the invention.

What is claimed is:
 1. An orthopedic cutting guide system for preciseplanar cutting of bony tissue in association with orthopedic surgicalprocedures, the system comprising: an alignment device adapted tosupport a surgical bone cutting saw, said saw having a generally planarsaw blade, said saw being supported by said alignment device such thatmovement of said blade is substantially fixed in a plane coplanar withthe plane of said blade relative to said alignment device but free tomove translationally and rotationally relative to said alignment device,said alignment device further being oriented so that a long axis thereofextends generally outward and away from said bony tissue; and a cuttingguide adapted to be removably attached to a bone and further adapted toreleasably receive said alignment device in at least one nonadjustable,substantially fixed position, said fixed position being preciselyangularly oriented relative to said cutting guide and wherein said sawblade is passable through an aperture closely approximating a leastdimension of said saw blade.
 2. The orthopedic cutting guide system asclaimed in claim 1, further comprising a carriage adapted to supportsaid surgical bone cutting saw while allowing said saw to translatealong and rotate relative to said alignment device.
 3. The orthopediccutting guide system as claimed in claim 1, in which said bone comprisesa long bone having a longitudinal mechanical axis, said cutting guidecomprising an attachment member adapted such that said alignment deviceis engaged to said bone such that said saw cuts a planar surfacegenerally orthogonal to said longitudinal mechanical axis.
 4. Theorthopedic cutting guide system as claimed in claim 1, in which saidbone comprises a long bone having a long axis, said cutting guidecomprising an attachment member adapted such that said alignment deviceis engaged to said bone such that said saw cuts a planar surfacegenerally oblique to said longitudinal mechanical axis.
 5. Theorthopedic cutting guide system as claimed in claim 1, in which saidbone comprises a long bone having a longitudinal mechanical axis, saidcutting guide comprising an attachment member adapted such that saidalignment device is engaged to said bone engaged such that said saw cutsa planar surface generally parallel to said longitudinal mechanicalaxis.
 6. The orthopedic cutting guide system as claimed in claim 1, inwhich said cutting guide is removably attached to said bone by a meansselected from a group consisting of clamps, screws, pins, adhesives anddrill bits.
 7. The orthopedic cutting guide system as claimed in claim1, in which said alignment device is releasably secured to said cuttingguide by at least one attachment member.
 8. The orthopedic cutting guidesystem as claimed in claim 1, said cutting guide further definingalignment member receivers and said alignment device further comprisingalignment members whereby said alignment device is precisely alignedwith and releasably attached to said cutting guide.
 9. The orthopediccutting guide system as claimed in claim 1, in which said aperture isdefined by said cutting guide.
 10. The orthopedic cutting guide systemas claimed in claim 1, in which said aperture is defined by saidalignment device.
 11. The orthopedic cutting guide system as claimed inclaim 1, in which said aperture is defined in part by said cutting guideand in part by said alignment device.
 12. The orthopedic cutting guidesystem as claimed in claim 1, said cutting guide further comprisingselectively attachable handlebars whereby a surgical assistant may graspand stabilize said cutting guide.
 13. The orthopedic cutting guidesystem as claimed in claim 1, further comprising a selectivelyattachable femoral reference to aid locating said cutting guide.
 14. Theorthopedic cutting guide system as claimed in claim 1, in which saidalignment device and said cutting guide are an integral unit.
 15. Theorthopedic cutting guide system as claimed in claim 2, in which saidcarriage movably engages with said alignment device via a mechanismselected from a group consisting of bushings, roller bearings, ballbearings and sliding bearings.
 16. The orthopedic cutting guide systemas claimed in claim 1, in which said alignment device is releasablysecured to said cutting guide via a mechanism selected from a groupconsisting of pegs, clips, screws, pins, bayonet fit and friction fit.17. The orthopedic cutting guide system as claimed in claim 2, in whichsaid carriage is secured to said surgical bone cutting saw by a meansselected from a group consisting of screws, adhesives, clamping, pegs,clips, screws, pins, bayonet fit and a friction fit.
 18. A method forprecise planar cutting of bony tissue in association with orthopedicsurgical procedures, the method comprising the steps of: removablyattaching a cutting guide to a bone; removably securing an alignmentdevice adapted to support a surgical bone cutting saw, said saw having agenerally planar saw blade, said alignment device supporting said sawsuch that said blade is substantially fixed in a plane generallycoplanar with the plane of said blade relative to said alignment devicebut free to move translationally and rotationally relative to saidalignment device; advancing said saw axially along said rack andmanipulating said saw rotationally so as to cut said bone to create adesired first planar cut bone surface.
 19. The method as claimed inclaim 18, further comprising the step of relocating said cutting guideto a second location secured to said bone, said second location beingchosen so as to allow the making of a second and additional planarsurfaces precisely aligned relative to said first planar cut bonesurface.
 20. The method as claimed in claim 18, further comprising thestep of utilizing a selectively attachable femoral reference to aidlocating said cutting guide for creating said second and additionalplanar surfaces.
 21. The method as claimed in claim 18, furthercomprising the step of attaching selectively attachable handlebarswhereby a surgical assistant may grasp and stabilize said cutting guide.22. An orthopedic cutting guide system for precise planar cutting ofbony tissue in association with orthopedic surgical procedures, thesystem comprising: means for supporting a surgical saw having agenerally planar saw blade such that said saw blade is substantiallyfixed in a pitch axis and a roll axis but free to move in a yaw axis andto translate axially relative to said supporting means; means forguiding said saw blade, said guiding means adapted to be removablysecured to a bone, and said guiding means comprising means forremovably, substantially rigidly receiving said supporting means wherebysaid surgical saw can be translated and yawed in order to prepare aprecision cut substantially planar bone surface.
 23. The orthopediccutting guide system as claimed in claim 22, further comprising acarriage adapted to support said surgical bone cutting saw whileallowing said saw to translate along and rotate relative to saidsupporting means.
 24. The orthopedic cutting guide system as claimed inclaim 22, in which said bony tissue comprises a long bone having alongitudinal mechanical axis, said guiding means comprising anattachment member adapted such that said supporting means is engaged tosaid bone such that said saw cuts a planar surface generally orthogonalto said longitudinal mechanical axis.
 25. The orthopedic cutting guidesystem as claimed in claim 22, in which said bony tissue comprises along bone having a longitudinal mechanical axis, said guiding meanscomprising an attachment member adapted such that said alignment deviceis engaged to said bone such that said saw cuts a planar surfacegenerally oblique to said longitudinal mechanical axis.
 26. Theorthopedic cutting guide system as claimed in claim 22, in which saidbony tissue comprises a long bone having a longitudinal mechanical axis,said guiding means comprising an attachment member adapted such thatsaid alignment device is engaged to said bone engaged such that said sawcuts a planar surface generally parallel to said long axis.
 27. Theorthopedic cutting guide system as claimed in claim 22, in which saidguiding means is removably fixated to said bone by a means selected froma group consisting of clamps, screws, pins and drill bits.
 28. Theorthopedic cutting guide system as claimed in claim 22, in which saidalignment device is releasably secured to said guiding means by at leastone attachment member.
 29. The orthopedic cutting guide system asclaimed in claim 22, said guiding means further defining alignmentmember receivers and said alignment device further comprising alignmentmembers whereby said alignment device is precisely aligned andreleasably attached to said cutting guide.
 30. The orthopedic cuttingguide system as claimed in claim 22, in which an aperture closelyapproximating a least dimension of said saw blade is defined by saidguiding means.
 31. The orthopedic cutting guide system as claimed inclaim 22, in which an aperture closely approximating a least dimensionof said saw blade is defined by said alignment device.
 32. Theorthopedic cutting guide system as claimed in claim 22, in which anaperture closely approximating a least dimension of said saw blade isdefined in part by said guiding means and in part by said alignmentdevice.
 33. The orthopedic cutting guide system as claimed in claim 22,said cutting guide further comprising selectively attachable handlebarswhereby a surgical assistant may grasp and stabilize said cutting guide.34. The orthopedic cutting guide system as claimed in claim 22, furthercomprising a selectively attachable femoral reference to aid locatingsaid guiding means.
 35. The orthopedic cutting guide system as claimedin claim 22, further comprising a femoral reference to aid locating saidguiding means.
 36. An orthopedic cutting guide system for precisecutting of bony tissue in association with orthopedic surgicalprocedures, the system comprising: a curved alignment device adapted tosupport a surgical bone cutting saw, said saw being supported such thatmovement of said saw is substantially fixed in parallel relationshiprelative to said alignment device but free to move translationally androtationally relative to said alignment device, said alignment devicefurther being oriented so that a path of travel of said saw along saidalignment device extends generally across said bony tissue; and acutting guide adapted to be removably fixated directly to a bone. 37.The orthopedic cutting guide system as claimed in claim 36, furthercomprising a carriage adapted to support said surgical bone cutting sawwhile allowing said saw to move in a parallel fashion relative to saidalignment device.
 38. The orthopedic cutting guide system as claimed inclaim 36, in which said cutting guide is removably fixated to said boneby a means selected from a group consisting of clamps, screws, pins,adhesives and drill bits.
 39. The orthopedic cutting guide system asclaimed in claim 36, in which said alignment device is releasablysecured to said cutting guide by at least one attachment member.
 40. Theorthopedic cutting guide system as claimed in claim 36, said cuttingguide further defining alignment member receivers and said alignmentdevice further comprising alignment members whereby said alignmentdevice is precisely aligned and releasably attached to said cuttingguide.
 41. The orthopedic cutting guide system as claimed in claim 36,said cutting guide further comprising selectively attachable handlebarswhereby a surgical assistant may grasp and stabilize said cutting guide.42. The orthopedic cutting guide system as claimed in claim 36, furthercomprising a selectively attachable femoral reference to aid locatingsaid cutting guide.
 43. The orthopedic cutting guide system as claimedin claim 36, in which said alignment device and said cutting guide arean integral unit.
 44. The orthopedic cutting guide system as claimed inclaim 36, in which said alignment device is releasably secured to saidcutting guide via a mechanism selected from a group consisting of pegs,clips, screws, pins, bayonet fit and friction fit.
 45. The orthopediccutting guide system as claimed in claim 37, in which said carriagemovably engages with said alignment device via a mechanism selected froma group consisting of bushings, roller bearings, ball bearings andsliding bearings.
 46. The orthopedic cutting guide system as claimed inclaim 37, in which said carriage is secured to said surgical bonecutting saw by a means selected from a group consisting of screws,adhesives, clamping, pegs, clips, screws, pins, bayonet fit and frictionfit.
 47. A method for precise planar cutting of bony tissue inassociation with orthopedic surgical procedures, in which the methodachieves a percentage of contact between a resected bone surface and aplanar prosthesis surface greater than about 32%.
 48. A method forprecise planar cutting of bony tissue in association with orthopedicsurgical procedures, in which the method consistently achieves anangular difference between planar resected lateral femoral condyles andmedial femoral condyles of less than about 0.5 degrees.
 49. A method forprecise planar cutting of bony tissue in association with orthopedicsurgical procedures, in which the method consistently prevents contactbetween a surgical saw blade and a guide slot such that wear and damageto surgical saw blade teeth are minimized.
 50. A method for preciseplanar cutting of bony tissue in association with orthopedic surgicalprocedures, in which the method consistently achieves a surfaceprecision that results in a gap between an orthopedic prosthesis surfaceand a resected bone surface of less than about 0.5 millimeters.
 51. Amethod for precise planar cutting of bony tissue in association withorthopedic surgical procedures, in which the method consistentlyachieves a planar cutting error of plus or minus about 1.0 millimeter.52. An orthopedic cutting guide system for precise planar cutting ofbony tissue in association with orthopedic surgical procedures, thesystem comprising: an alignment device cutting guide comprising analignment device portion and a cutting guide portion; the alignmentdevice portion adapted to support a surgical bone cutting saw, said sawhaving a generally planar saw blade, said saw being supported by saidalignment device such that movement of said blade is substantially fixedin a plane coplanar with the plane of said blade relative to saidalignment device portion but free to move translationally androtationally relative to said alignment device portion, said alignmentdevice portion further being oriented so that a long axis thereofextends generally outward and away from said bony tissue; and thecutting guide portion adapted to be removably attached to a bone andfurther adapted to support said alignment device portion in anonadjustable, substantially fixed position, said fixed position beingprecisely angularly oriented relative to said cutting guide and whereinsaid saw blade is passable through an aperture closely approximating aleast dimension of said saw blade.
 53. The orthopedic cutting guidesystem as claimed in claim 52, further comprising a carriage adapted tosupport said surgical bone cutting saw while allowing said saw totranslate along and rotate relative to said alignment device portion.54. The orthopedic cutting guide system as claimed in claim 52, in whichsaid bone comprises a long bone having a longitudinal mechanical axis,said cutting guide comprising an attachment member adapted such thatsaid alignment device portion is engaged to said bone such that said sawcuts a planar surface generally orthogonal to said longitudinalmechanical axis.
 55. The orthopedic cutting guide system as claimed inclaim 52, in which said bone comprises a long bone having a long axis,said cutting guide comprising an attachment member adapted such thatsaid alignment device portion is engaged to said bone such that said sawcuts a planar surface generally oblique to said longitudinal mechanicalaxis.
 56. The orthopedic cutting guide system as claimed in claim 52, inwhich said bone comprises a long bone having a longitudinal mechanicalaxis, said cutting guide comprising an attachment member adapted suchthat said alignment device portion is engaged to said bone engaged suchthat said saw cuts a planar surface generally parallel to saidlongitudinal mechanical axis.
 57. The orthopedic cutting guide system asclaimed in claim 52, in which said cutting guide portion is removablyattached to said bone by a means selected from a group consisting ofclamps, screws, pins, adhesives and drill bits.
 58. The orthopediccutting guide system as claimed in claim 52, in which said alignmentdevice portion is releasably secured to said cutting guide by at leastone attachment member.
 59. The orthopedic cutting guide system asclaimed in claim 52, in which said aperture is defined by said cuttingguide portion.
 60. The orthopedic cutting guide system as claimed inclaim 52, in which said aperture is defined by said alignment deviceportion.
 61. The orthopedic cutting guide system as claimed in claim 52,in which said aperture is defined in part by said cutting guide and inpart by said alignment device.
 62. The orthopedic cutting guide systemas claimed in claim 52, said cutting guide portion further comprisingselectively attachable handlebars whereby a surgical assistant may graspand stabilize said cutting guide.
 63. The orthopedic cutting guidesystem as claimed in claim 52, further comprising a femoral reference toaid locating said cutting guide portion.
 64. The orthopedic cuttingguide system as claimed in claim 53, in which said carriage movablyengages with said alignment device via a mechanism selected from a groupconsisting of bushings, roller bearings, ball bearings and slidingbearings.
 65. The orthopedic cutting guide system as claimed in claim52, in which said alignment device is releasably secured to said cuttingguide via a mechanism selected from a group consisting of pegs, clips,screws, pins, bayonet fit and friction fit.
 66. The orthopedic cuttingguide system as claimed in claim 52, in which said carriage is securedto said surgical bone cutting saw by a means selected from a groupconsisting of screws, adhesives, clamping, pegs, clips, screws, pins,bayonet fit and a friction fit.